Marine anchor



Oct. 25, 1966 c. H. HOLM 3,280,782

MARINE ANCHOR Filed May 24, 1965 l IVI r 1 "V CARL H. HoLM ATTORNEYUnited States Patent O 3,280,782 MARINE ANCHOR Carl H. Holm, MiamiBeach, Fla., assignor to North American Aviation, Inc. Filed May 24,1965, Ser. No. 457,956 4 Claims. (Cl. 114-206) This invention relatesgenerally to marine anchors, and particularly concerns an anchorassembly having provisions for forcible anchor iluke embedment. From anapplications standpoint, the invention is considered especially usefulin instances where taut line mooring is required.

The instant marine anchor invention is essentially comprised of acylinder and a piston-driven anchor shaft having attached outwardlyrotatable anchor llukes. The piston-driven anchor shaft is powered forembedment purposes essentially by environmental water. The interior ofthe cylinder normally contains air at ambient atmospheric pressure andat the time of anchor actuation iluid openings in the cylinder upperexterior are uncovered permitting environmental water to ilow into thecylinder upper interior and act upon the piston; forces developed fromthe pressure difference between environmental hydrostatic pressure andthe atmospheric pressure of the contained air compress the air containedin the cylinder lower interior below the piston and rapidly deployportions of the anchor shaft and the extending anchor lukes downwardlyinto the anchoring medium. Such embedment is accomplished by theinvention without requiring the use of an explosive propellant charge.

A primary object of this invention is to provide a marine anchorassembly with means to advantageously utilize environmental water andthe hydrostatic pressure condition associated therewith foraccomplishing anchor shaft and anchor lluke embedment.

Another object of this invention is to provide a marine anchor assemblyutilizing environmental water and the hydrostatic pressure conditionassociated therewith to accomplish anchor shaft and anchor ilukeembedment with a construction and means to develop comparatively highanchor shaft embedment accelerations from such hydrostatic pressurecondition.

A still further object of this invention is to provide a marine anchorassembly with a construction that does not incorporate or require theuse of an explosive propellant charge to develop the forces necessaryfor accomplishing adequate anchor lluke embedment.

Other objects and advantages of this invention will become apparentduring consideration of the following specification and drawings.

In the drawings:

FIG. l is a combined elevational and sectional view of a preferredembodiment of the marine anchor assembly of this invention;

FIGS. 2. and 3 are partial sectional and plan views showing additionaldetails of the marine anchor assembly of FIG. l; and

FIGS. 4 through 6 are elevational views showing the marine anchorassembly of FIGS. 1 and 2 at various stages in a typical deployment.

A preferred embodiment of the marine anchor invention of thisapplication is designated in the drawings. In the FIG. l View it isillustrated as being suspended from the lower extreme of anchoring cable11 by means of attachment bail 12. The object to be anchored is normallysecured to assembly 10 at the other extreme of anchor line 11. For tautline mooring applications wherein it is desired that a damping weight beutilized, a cable 13 may be provided to connect the principal mass ofassembly 10 to the embedded portions in spaced-apart relation and afterseparation for that purpose.

Patented Oct. 25, 1966 ice Anchor assembly 10 is essentially comprisedof hollow cylinder 14, interiorly-contained piston element 15, anchorshaft 16, and an operator 17-initiator 18 combination for operativelyinitiating actuation of assembly 10. Cylinder 14 is provided with endflanges 19 and 20 that carry lower and upper end caps 21 and 22,respectively, through conventional fasteners 23. Piston 15 is slidablycontained within cylinder 14 and is of suillcient length to interiorlycover the lluid inlet ports 24 provided in the upper exterior region ofcylinder 14. Recess 25 is provided in the upper end surface of piston 15to receive the sealing plug 26 when assembly 10 is actuated toaccomplish anchor shaft embedment; the recess 27 provided in the lowerend surface of piston 15 receives the upper end of shaft 16 in drivingrelation. The lower end of shaft 16 projects through a cooperatingopening in end cap 21 and carries the retracted outwardly rotatablellukes designated 28. A point configuration is preferably provided atthe lower extreme of shaft 16.

Assembly 10 is also preferably provided with a drag cone 29 in attachedrelation to the exterior of cylinder 14. Cone 29 functions to developadded resistance to reaction movement of cylinder 14 and aids inaccomplishing embedment of anchor shaft 16 and attached tlukes 28. Insome applications (extreme anchoring depths) and assembly configurations(high inherent drag) use of a drag cone such as 29 may not be necessary.

Operator member 17 is essentially in the form of a rod and is providedwith a foot portion 30; further, operator 17 is slidably supportedwithin the cooperating brackets that project laterally from end cap 21and end flange 20. The upper end of operator 17 cooperates with therotatable lever portion 31 of initiator 18.

As shown in FIG. 2 of the drawings, initiator 18 is secured to end cap22 by conventional fastener devices 32. The initiator includes aretainer slide 33 preferably having a keyhole slot 34; the narrowportion of slot 34 is normally engaged with the illustrated peripheralrecess provided in the upper portion of sealing plug 26 and retainssealing plug 26 in its illustrated FIG. 2 position until anchor 10 isactuated by sulllcient upward movement of operator rod 17.

Also, as shown in the drawings, a tensioned spring 35 is provided ininitiator 18 to preload slide 33 and also the over-center detentmechanism designated 36. A shear pin 37 may be provided t-o supplmentdetent -device 36 and thereby minimizes accidental operation of lever 31if desired; also, a pin 38 may be utilized to facilitate the assembly ofanchor 10 during manufacture by retaining slide 33 in its restrainingposition but it must be removed prior to anchor deployment. Projectingears may be included on slide 33 (FIG. 3) for cooperation with stopsprovided in the illustrated side flanges of lever arm 31 (FIG. l). Thisarrangement serves to retain slide 3-3 and sealing plug 26 in their FIG.2 restrained position so long as lever 311 is not moved upwardly. Whenlever arm 31 is rotated by rod 17 about pin 39, the stops of the sidesof lever 31 are disengaged from the side-projecting ears of slide 33 andspring '35 then moves the large portion of keyhole slot 34 intosurrounding relation to sealing plug 26. Plug 26 then is freed to movedownwardly within the cooperating continuous cylindrical passageway 40`in end cap 22 and initiator 18. Hydrostatic forces acting upon the upperend of sealing plug 26 will, when -anchor assembly 10 is actuated andproviding the associated hydrostatic pressure is greater than thepressure of the interiorly contained air, force plug 26 into recess 25to accomplish initial flooding of the upper interior portion of hollowcylinder 14.

Several other construction features of anchor assembly 10 are ofinterest. Conventional O-ring seals 41 are provided -at obviouslocations throughout assembly 10 to seal the interior of cylinder 14from exterior environmental pressure conditions. At the time of assemblythe normal exterior environmental pressure, and thus the conditionwithin cylinder 14, is ambient atmospheric pressure. Lug 42 is attachedto shaft 16 to assist in securing portion 13 of anchor line 11 to thelower extreme of the assembly. A shear pin (not shown) may be providedin assembly to retain shaft 16 in its FIG. 1 position during normalhandling; such shear pin, however, should not interfere with theactua-tion of assembly 10. The .top of piston is preferably spaced apartfrom the under-surface of end cap 22 (FIG. 2). At the time of anchormanufacture a collar 43 is connected to sh-aft 16 to assure thenecessary degree of spacing.

As suggested above, anchor -assembly 10 is fabricated using conventionalmanufacturing techniques and when assembled includes air at .ambientatmospheric pressures within cylinder 14. As assembly 10 is lowered toconsiderable depths, the environmental medium (water) establishessubstantial pressure differentials between the cylinder exterior andinterior. The pressure differential which exists at the anchoring depthis employed to obtain the advantages of this invention.

A prototype anchor assembly 10 having 4a hollow cylinder 14approximately 6 feet long was provided with a cooperating piston 15 ofapproximately 5 inches diameter. The piston length was approximately 10inches to cover an arrangement of two circumferential rows of live uidinlets each in the cylinder upper exterior region; each inlet openinghad a diameter of approximately 1% inches. The drag cone 29 attached tocylinder 14 had an -overall diameter of approximately 3 feet. A hollowanchor shaft `16 that was 1% inches in diameter extended from piston 15and through the lower end of the cylinder by a distance of approximatelyinches; the projecting anchor shaft was provided with two generallyopposed rotatable anchor fiukes 28 each having an overall length ofapproximately 7 inches extended. The prototype unit was assembled undernormal conditions so that the unoccupied interior of cylinder 14contained air at standard atmospheric pressure.

Assembly 10 was lowered at sea approximately 1,000 feet to bottom andwas actuated in the manner shown by FIGS. 4 through 6. On contact withanchoring medium 45, reaction forces introduced into rod 17 at footportion 30 cause upward movement of initiator lever 31 relative to theanchor assembly. A small degree of clockwise (FIG. 2) rotation lof leverarm 31 about axis 39 released slide 33 for movement by tensioned spring35. Movement of slide 33 resulted in disengagement of sealing plug 26from restraint within keyhole slot34 thus permitting the environmentalhydrostatic pressures (approximately 450 psi.) to force sealing plug 26into recess 25 and thereby open passageway 40. Seal water ported throughpassageway 40 into the space intermediate piston 15 and end cap 22caused `downward displace-ment of piston 1S and initial compression ofthe air at atmospheric pressure within the unoccupied lower interiorportion of cylinder 14. Such relative downward displacement of piston 1Sfurther caused the complete opening of fluid inlets 24 thereby admittingfluid at environmental hydrostatic pressures into the cylinder interiorintermediate end cap 22 and upper surface of downwardly displaced piston-15 at a high how rate thereby causing piston 1S to further compress theair in cylinder 14 to an equilibrium pressure. The rapid compression ofcontained atmospheric air is accompanied by comparatively highrelatively downward acceleration of shaft 16 in opposition to reactioninertia of cylinder 14 and the components carried thereby and also inopposition to the resistance resulting from drag cone 29 if employed inthe invention construction. Such rapid downward acceleration inopposition to the concurrent reaction forces causes a substantialpenetration of shaft 16 and attached anchor flukes 28 into the anchoringmedium 4S. See FIG. 5. On completion of anchor shaft and flukeembedment, underwater turbulence forces -acting on anchored sonobuoy 44(the object to be anchored) and through anchoring cable 11 may beutilized to disengage cylinder 14 from shaft 16. The mass of cylinder 14provides a damping effect for taut line mooring applications yet cable11 remains connected to shaft 16 through cable section 13. Withdrawalforces acting upon anchoring cable section 13 cause limited withdrawalof anchor shaft 16 and simultaneous rotation of anchor flu-kes 28 to anextended position. FIG. 6 shows assembly 10 in its typical finallydeployed condition.

It is to be understood that the forms of the invention herewith shownand described are to be taken as preferred embodiments of the s-ame, butthat various changes in the proportioning, size, and detail of parts maybe resorted to without departing from the spirit of the invention or thescope of 4the subjoined claims.

I claim:

1. A marine ancho-r assembly for actuation by environmental fluid having`an associated hydnostatic pressure that substantially exceedsatmospheric pressure, and comprising:

(a) Hollow cylinder means having closed upper and lower ends 'and havingan interior that contains gas at a pressure essentially corresponding toatmospheric pressure,

(b) Anchor shaft means partially within said cylinder means interior andslidably projecting through. said cylinder means closed lower end withattached anchor nukes positioned below said cylinder means,

(c) Piston means cooperatively positioned in said cylinder means indriving relation to said anchor shaft means and separating said cylindermeans interior i-nto yupper and `lower portions each of variable volume,and

(d) Inlet port means located in the upper region of said cylinder meansand arranged to conduct actuating environmental fluid from regionsexterior to the 4anchor assembly into said cylinder means upper interiorportion when opened,

said inlet port means being closed [from communication with saidcylinder means upper interior portion by said piston means prior toactuation of the anchor assembly and being opened as a result of initialdownward movement of said piston means relative tosaid cylinder means tothereby conduct suicient @actuating environmental fiuid into saidcylinder means upper interior portion to continuously 4compress the gascontained in said cylinder means lower interior portion to anequilibrium pressure corresponding to the hydrostatic pressure of theenvironmental iiuid, to substantially accelerate lsaid piston means .andsaid anchor shaft means downwardly relative to said cylinder means, andto consequently embed said .anchor shaft means in an anchoring medium.

2. rIlhe invention by claim 1, wherein said piston means is providedwith longitudinal spaced-apart seal means, and wherein said inlet portmeans is comprised of peripheral-ly positioned cylinder means openings,said piston means being positioned prior to actuation of the lanchorassembly so that said in'let port means is located intermediate saidlongitudinally spaced-apart seal means to further close said inlet portmeans fnom communication with said cylinder means interior upper andflower portions.

3. The invention defined by claim 1, wherein said cylinder means isadditionally provided with separate means positioned in cooperation withsaid cylinder means interior upper portion for initiating actuation ofthe marine yanchor assembly, said separate means conductingenvironmental iluid to said hollow cytlinder means interior rupperportion when actuated toy initially compress the gas contained in saidcylinder means lower interior portion and consequently move said pist-onmeans downwardly relative to said cylinder means asucient distance tochange said inlet port means from `a closed condition to an opencondition to additionally conduct environmental uid to said cylindermeans interior upper portion.

4. The invention defined by claim 3, wherein said separate meansincludes a passageway means extending from the yanchor assembly exteriorto said cylinder means interior upper portion, sealing plug meanspositioned in said passageway in longitudinal sliding relation, recessmeans in said cylinder means interior upper portion Ilarge enough tomore than completely receive said :sealing plug means,

and restraining means preventing longitudinal sliding lo movement ofsaid sealing plug means relative to said passageway and said recessmeans when engaged with said sealing plug means, said initiator meansdisengaiging said restraining means from said sliding plug means whenactuated to permit environmental fluid to cause said sealing 3,ll8,4l7114-206 MILTON BUCHLER, Primary Examiner.

T. M. BLIX, Assistant Examiner.

1. MARINE ANCHOR ASSEMBLY FOR ACTUATION BY ENVIRONMENTAL FLUID HAVING ANASSOCIATED HYDROSTATIC PRESSURE THAT SUBSTANTIALLY EXCEEDS ATMOSPHERICPRESSURE, AND COMPRISING: (A) HOLLOW CYLINDER MEANS HAVING CLOSED UPPERAND LOWER ENDS AND HAVING AN INTERIOR THAT CONTAINS GAS AT A PRESSUREESSENTIALLY CORRESPONDING TO ATMOSPHERIC PRESSURE, (B) ANCHOR SHAFTMEANS PARTIALLY WITHIN SAID CYLINDER MEANS INTERIOR AND SLIDABLYPROJECTING THROUGH SAID CYLINDER MEANS CLOSED LOWER WITH ATTACHED ANCHORFLUKES POSITIONED BELOW SAID CYLINDER MEANS, (C) PISTON MEANSCOOPERATIVELY POSITIONED IN SAID CYLINDER MEANS IN DRIVING RELATION TOSAID ANCHOR SHAFT MEANS AND SEPARATING SAID CYLINDER MEANS INTERIOR INTOUPPER AND LOWER PORTIONS EACH OF VARIABLE VOLUME, AND (D) INLET PORTMEANS LOCATED IN THE UPPER REGION OF SAID CYLINDER MEANS AND ARRANGED TOCONDUCT ACTUATING ENVIRONMENTAL FLUID FROM REGIONS EXTERIOR TO THEANCHOR ASSEMBLY INTO SAID CYLINDER MEANS UPPER INTERIOR PORTION OPENED,